Research And Application Of The Key Based On PCS Intelligent Micro Grid System

Energy is an essential material basis for human survival and development.Because of the low utilization ratio of energy and the energy structure imbalance led to the deterioration of the ecological environment, new energy power generation has been rapidly developed.At present, solar energy, wind energy, biomass and other renewable energy power generation have gradually formed the scale in China, most of the region’s renewable energy power generation is in the form of distributed power supply.The distributed generation system can make full use of renewable energy to generate electricity and improve the efficiency and security of supply reliability. However, with the development of distributed generation, the power system is facing some new problems and challenges.As the distributed generation is intermittent, scattered and random,so with the traditional synchronous generator and more and more distributed generation are connected to utility, which will bring some negative impact on the control and operation of the power system.The biggest advantage of smart micro grid system is that it can integrate the distributed power generation system and connect the distributed power supply to the same power network. Using the controlling device and the protection device as grid-tied buffer, so that it can weak the adverse effects of distributed generation on the smart microgrid and guarantee the electric power network generation,load balance, voltage and frequency stability of power system.Therefore, the smart micro grid has become a hot research in the development of new energy sources.Research on the control method based on the smart micro grid energy storage power generation system and the corresponding control strategies in this paper. Based on a smart microgrid system experimental platform, simulated results on MALAB and experimental results were utilized to confirm the relevant research results, and provide a theoretical basis and practical basis for the further research work. The main research contents are as follows:(1)Build a smart microgrid experimental platform, and study some of the key technical problems in smart microgrid;(2) Establish the mathematical model of energy storage converter, and use the grid-tied and standalone control methods based on the energy storage converter to compensate the system reactive power at the same time;(3) Analyze the impact on the power system of unbalanced load and then decouple the unbalanced load current in the positive and negative double synchronous rotating coordinate to suppress the negative sequence component of grid-connected current;(4) Using the energy storage converter to improve the intermittent problem of photovoltaic power generation system and confirm the validation according to the actual working conditions;(5) The virtual synchronous machine (VSG) control strategy is proposed, implement the parallel operation of the energy storage converters and experiment with load is carried out;(6) Realize the seamless transfer in the smart micro grid, and the control strategy is proposed to detect the active and passive isolated island, then the seamless transfer is validated by experiment.